Efficacy of Etoricoxib on Peripheral Hyperalgesia

Inclusion Criteria: * Patients over 18 years with * Persistent moderate or severe pain (\> 4 on NRS (1..10)) at rest (average of three daily assessments using a diary for at least two days) . * Neuropathic pain associated with a clinical and neurologically proven peripheral nerve injury, radiculopathy, postherpetic neuralgia or polyneuropathy or CRPS * One of the two following QST phenotypes at the baseline assessment: * signs of peripheral hyperalgesia (that means, pathological decreased heat pain threshold and/or pathological decreased muscle pain threshold) * without signs of peripheral hyperalgesia (no pathological decreased heat - and/or muscle pain threshold) * Patients of both gender * Signed consent form * Patients with the ability to understand and follow the instructions of the doctor Exclusion Criteria: * Excluded will be patients Parkinson's disease or a history of cerebral vascular insult or nerve injury. Excluded will be also all patients with contradictions for the use of Etoricoxib: * Hypersensitivity to the active substance or to any of the excipients. * Active peptic ulceration or active gastrointestinal (GI) bleeding. * Patients who have experienced bronchospasm, acute rhinitis, nasal polyps, angioneurotic oedema, urticaria, or allergic-type reactions after taking acetyl-salicylic acid or NSAIDs including COX-2 (cyclooxygenase-2) inhibitors. * Pregnancy and lactation * Severe hepatic dysfunction (serum albumin \<25 g/l or Child-Pugh score ≥10). * Estimated renal creatinine clearance \<30 ml/min. * Inflammatory bowel disease. * Congestive heart failure (NYHA II-IV). * Patients with hypertension whose blood pressure is persistently elevated above 140/90mmHg and has not been adequately controlled * Established ischemic heart disease, peripheral arterial disease, and/or cerebrovascular disease. * Intake of one of the following drugs (current or in the last 3 days) * selective-serotonin-reuptake-inhibitor * cetoconazole * rifampicin * phenytoin * carbamazepine * dexamethasone or other systemic corticoids * traditional nonsteroidal antiphlogistics * cyclooxygenase-inhibitors * immunosuppressives * TNF-α-inhibitors